The present invention relates to air diffusers for hairdryers.
Handheld warm air hairdryers generally produce a narrow stream of warm air. If it is desired to produce a more even distribution of the warm air, then an air diffuser may be fitted to the barrel of the hairdryer for this purpose.
Most conventional air diffusers suffer from the disadvantage that they are awkward to use. In particular, the combined hairdryer and diffuser is substantially longer than the hairdryer alone and is difficult to manipulate especially when drying hair on the crown of the head or hair at the back of the head.
A diffuser which attempts to overcome the above problem consists of a diffuser neck and diffuser head, the diffuser neck being attachable co-axially to the barrel of the hairdryer, and the diffuser head being at an angle to the diffuser neck. This diffuser is much easier to manipulate. In particular, when drying for example hair on the crown of the head, the user can hold the hairdryer to one side of his head, and is not obliged to stretch his arms up to directly above the crown of his head.
However, the diffuser with the angled head is inefficient, the inefficiency arising as follows. Air from the hairdryer is driven along the diffuser neck, enters the angled diffuser head, and is then deflected by the internal surface of the diffuser head out through the diffuser mouth. The long path which the air travels, together with the deflection of the air in the diffuser head and consequent turbulence, gives rise to a risk of back pressure and overheating in the hairdryer. To overcome this problem, a number of vents are provided in the diffuser head, so that a proportion of the air driven along the neck flows directly out through the vents, thus reducing the possibility of back pressure. This proportion of heated air is therefore wasted.
An object of the present invention is to provide an air diffuser which is easy to manipulate and efficient in operation.
The present invention provides an air diffuser for attachment to a handheld hairdryer, comprising a diffuser neck, an angled diffuser head, and air vents to prevent back pressure and overheating, characterized in that the air vents are provided in the diffuser neck.
As hair is driven along the diffuser neck, if no back pressure builds up then substantially all of the air flows to the diffuser head and out through the diffuser mouth to dry the hair. However, if a back pressure builds up this will cause air to be vented through the air vents in the neck, thereby eliminating the risk o overheating. The air vents therefore come into play only as required.